1. Field of the Invention
The present invention pertains to photographic cameras and, more particularly, to multiple exposure control mechanisms for photographic cameras of the type having a film magazine with a take-up spool driven when the shutter in a camera body is cocked.
2. Discussion of the Prior Art
Photographic cameras of the type having a film magazine coupled with a camera body, such as the Hasselblad camera manufactured by Victor Hasselblad Aktiebolag of Goteborg, Sweden, conventionally advance film from a supply spool to a take-up spool in response to manual or powered cocking of the shutter in the camera body by transmitting power to a film take-up gear which pulls the film from the supply spool to a position of exposure and winds the film onto the take-up spool. The winding action in the film magazine is, thus, mechanically connected to the shutter cocking mechanism of the camera body and ensures that whenever the shutter is cocked, the film is advanced one frame to prevent the accidental multiple exposure of any particular frame of film. However, there are occasions when photographers want to intentionally multiple expose a single frame of film to achieve artistic effects and for other reasons. When a photographer desires to multiple expose a particular frame of film using a Hasselblad camera, the camera must be cocked by manually or electrically activating the shutter cocking mechanism in the camera body to lower the mirror, cock and open the shutter, and advance the film one frame. The camera is thereafter aimed and focused at the desired scene or subject to be photographed, and the shutter release button is activated to permit exposure of the film frame to the light reflected from the desired scene or subject. A light shield is then inserted into the film magazine to protect the exposed frame of film from additional light, and the film magazine is detached from the camera body, the light shield preventing any light from striking the previously exposed film frame. The shutter cocking mechanism is now recocked; and, since the film magazine is detached from the camera body, the position of the previously exposed film frame is not affected. The film magazine is now reattached to the camera body, and the light shield is removed from the magazine such that the previously exposed film frame is now in a position to be re-exposed when the shutter is activated. The photographer now aims and focuses the camera at the scene or subject which is desired to be super-imposed on the previously exposed film frame, and, when the shutter release button is activated, light from the desired scene or subject is reflected onto the previously exposed film frame to create a double exposure. If additional exposures on the same film frame are desired, the photographer must repeat the above steps.
The steps required to multiple expose film frames, as above described, have the disadvantages of being awkward, cumbersome and time consuming and represent a deterrent to the obtention of desired photographic effects by photographers. Accordingly, Hasselblad has developed a camera, Model 2000FC, permitting multiple exposures without detaching the film magazine from the camera body; however, this feature is incorporated in the camera body and not in the film magazine and, thus, prior camera models cannot be modified to selectively permit multiple exposures using this concept.
U.S. Pat. Nos. 2,218,241 to Hughey, 2,345,999 to Babcock, 2,559,880 to Kesel et al, 2,672,797 to Blattner, 2,819.664 to Elton, 2,868,099 to Weiss, 3,621,770 to Tsuruoka, 3,687,039 to Furuta, 3,688,671 to Irwin, 3,829,876 to Uno et al, 3,864,706 to Urano, 3,911,456 to Umemura, 3,968,508 to Ikeuchi and 4,017,875 to Yamamichi are representative of prior art mechanisms permitting multiple exposures with photographic cameras; however, none of these mechanisms are of a design and simplicity to allow modification of existing film magazines to permit multiple exposing of film frames.